1. Field of the Invention
The invention relates to an actuating device for opening and closing the folding roof of a motor vehicle with a bearing carriage which is movably supported on the roof-side guideway and which is connected to the movable part of the folding roof, and with a drive means which is connected to the bearing carriage by means of a drive carriage which is supported on the roof-side guideway and a connecting rod arrangement which has a toggle lever and which is controlled by a control crank, on the last closing path, the connecting rod arrangement stepping down the drive motion of the drive carriage.
2. Description of Related Art
Published European Patent Application EP 0 755 815 A1 shows a folding roof with such an actuating device, in which a drive carriage which is movably guided along a guideway is coupled via a toggle lever to the bow carrier of the end bow of the folding roof. The end section of the guideway swings the toggle lever relative to the drive carriage as when approaching the closed position. The swinging of the toggle lever causes the drive motion of the drive carriage to be stepped down. Aerodynamic forces which attack the end bow with the folding roof closed can be transferred via the toggle lever to the drive carriage, and thus, to the drive motor.
The primary object of the present invention is to provide a locking device having a simple structure and with which the folding roof can be reliably closed, and especially in the closed position, reaction forces on the drive will be prevented.
This object is achieved in accordance with the invention in the aforementioned locking device in that the toggle lever of the connecting rod arrangement, which is pivotally connected to the pivot arm of the bearing carriage, can be moved along a control guideway into its closed position in which it is located in a self-locking manner with respect to the opening force which acts on the bearing carriage via the roof part. This prevents the aerodynamic forces, which act on the folding roof when driving and which load the roof part out of its closed position on the apron in the direction of opening, from being able to act on the drive carriage, and thus, for example, via the drive cable on the drive means, for example, an electric drive motor. By connecting the toggle lever to the bearing carriage via the pivot lever the toggle lever can be accommodated in a space-saving manner in or on the guideway of the drive carriage while it is being pushed over the essential actuation path. The toggle lever is swung out only when approaching the closed position, the drive force being transferred continuously to the bearing carriage via the likewise pivoting pivot arm.
This object is also achieved in the aforementioned locking device with respect to improved operation in accordance with the invention in that the roof part is movably supported by a bearing means on the bearing carriage and the actuating motion of the bearing means is controlled by an additional control guide. Thus, an individual pivoting motion, superimposed on the lengthwise displacement, can be transmitted to the roof part which can press during the closing process, for example, from the top against a seal on the apron.
Preferably, the toggle lever is pivotally connected to the drive carriage by means of an intermediate lever. By means of the intermediate lever, the possibilities for kinematic displacement and arrangement of the toggle lever in its operating positions are increased.
In one preferred embodiment, the toggle lever, in its closed position, adjoins the control guide and the hinge of the pivot arm is located on the toggle lever between the engagement surface and the hinge which supports the intermediate lever. In the locked position, the toggle lever is at top dead center with respect to the pivot arm and supports the engagement surface in which it acts in a self-locking manner against forces which can act from the roof part on the bearing carriage and the pivot arm.
Feasibly, the engagement surface of the toggle lever is formed as a circular arc and the control guide is formed, in the closed position of the toggle lever, by the opposing engagement surface, which is especially likewise circularly shaped.
Preferably, the toggle lever, especially its back end, in its closed position, adjoins a stop which is opposite the engagement surface. Thus, the closed position or the self-locking dead center or top dead center position is clearly defined.
One advantage with respect to installation space arises from the fact that the toggle lever and the intermediate lever are guided to be unable to pivot on the guide rail which contains the guideway over the important actuating path, and only when approaching the closed position, can they swing out from the guideway by control by means of the control crank.
Especially when the swivel bearing of the swivel arm is located on the bearing carriage clearly above the guideway of the drive carriage, are the relationships of the forces on the bearing carriage, the swivel arm and the toggle lever advantageous for the behavior of the actuating device in motion.
If, preferably, the roof part is movably supported on the bearing carriage by a bearing means and the actuating motion of the bearing means is controlled by an additional control guide, an individual pivoting motion superimposed on the lengthwise displacement can be transmitted to the roof part which can press in the closing process, for example, from the above, against a seal on the apron.
To do this, it is feasible if the bearing means contains two connecting rods in a four-bar mechanism arrangement and if one of the connecting rods is guided on the additional control guide. This connecting rod can have two engagement elements, such as, for example, rollers or sliders which are guided on the additional control crank.
The actuating means is fundamentally suitable for all types of folding roofs which can close a roof opening in a fixed roof or a lowerable roof.
Embodiments of the locking device are explained in detail below with reference to the accompanying drawings.